The United States and Turkey kicked off on Thursday joint patrols of the northern Syrian city of Manbij, announced Turkish Defense Minister Hulusi Akar, according to state-run news agency Anadolu.
"The joint patrol in Manbij between Turkish armed forces and the US began today at 3.53pm (1253 GMT)," he told lawmakers.
The city is controlled by the US-backed Kurdish People's Protection Units (YPG), which Turkey considers a terrorist group.
The patrol took place around the Sajur River that divides Manbij and the region of Jarabulus, which was captured by Turkish-backed Syrian opposition factions from the ISIS terrorist group in 2016 during Ankara's first offensive in northern Syria.
A Reuters journalist saw a convoy of six military vehicles, some flying the US flag and others flying the Turkish flag, driving on Thursday about 20 km from Manbij city.
Sharfan Darwish, spokesman of the Manbij Military Council, told The Associated Press earlier that the patrols were taking place on the front lines between his group and those of Turkey-backed factions in the operation called Euphrates Shield.
Manbij was captured from ISIS by the Syrian Democratic Forces (SDF), an umbrella group dominated by the YPG.
Ankara has repeatedly threatened to attack the city and earlier this week President Recep Tayyip Erdogan said Turkey had completed preparations for a new operation to "destroy" the YPG in northern Syria.
There are US forces in the Manbij -- which lies just 30 kilometers (19 miles) south of the Turkish border -- and Washington has been closely working with the YPG in the fight against ISIS.
Maj. Gen. Christopher Ghika, deputy commander of operation Inherent Resolve, said recent training by Turkish and coalition forces will help them to protect Manbij civilians.
"We're fully supportive of the roadmap and the combined joint patrols, and I am confident they will be very effective," he said.
The US support of the YPG has strained relations with Turkey.
Ankara says the YPG is an offshoot of the outlawed Kurdistan Workers' Party (PKK), which has waged a bloody insurgency in Turkey since 1984 with the goal of forming an independent Kurdish state.
The PKK is blacklisted as a terror group by Turkey, the US and the European Union.
Earlier this year, Turkey and the US agreed the YPG would withdraw from Manbij.
As part of the roadmap, Turkish Foreign Minister Mevlut Cavusoglu at the time said the agreement would ensure the YPG leaves Manbij, then Turkey and the US would work together to establish a local security structure and decide who will govern the city.
Akar warned earlier Thursday that "the terror group (YPG) will be buried in the trenches it has dug".
